What is the simplified form of 17y - 12y? giving brainliest for first/ correct answer!

If you answer right ill give brainliest, : )

Adam plans to choose a video game from the section of the store where everything is 75% off. he writes the expression d-0.75d to find the sale price of the game if the original price is d dollars. gena correctly writes another expression, 0.25d, that will also find the sale price of the game if the original price is d dollars. use the drop down menus to explain each part of adams and rena's expression

What is the number 321,000,000 in scientific notation? also what is the number? ?